The plots of Rt over time continue to show a downward trend, started in early-to-mid-September in the Northern regions and early-October elsewhere, resulting in values below 1 in NE, NW, YH and close to 1 in the West Midlands.
The number of new infections has peaked in the NE NW and YH and plateaued in the East and West Midlands, but continues to increase in the SE, SW, EE and London.
Trends in the number of daily deaths occurring each day follow a similar pattern but with a lag of 2-3 weeks. The combination of these different patterns across regions explain the unusual shape of the estimated trends for deaths.
The lower values of Rt and the decrease in the number of new infections are likely to be resulting from the combination of social distancing interventions, half-term school closures as well as the most recent lockdown. This lock-down seems to have contributed to the continuation of the downwards trends, however this contribution appears quite modest.
Real-time tracking of an epidemic, as data accumulate over time, is an essential component of a public health response to a new outbreak. A team of statistical modellers at the MRC Biostatistics Unit (BSU), University of Cambridge, are working to provide regular now-casts and forecasts of COVID-19 infections and deaths. This information feeds directly to the SAGE sub-group, Scientific Pandemic Influenza sub-group on Modelling (SPI-M), and to regional Public Health England (PHE) teams.
We fit a transmission model (Birrell et al. 2020) to a number of data sources (see ‘Data Sources’), to reconstruct the number of new COVID-19 infections over time in different age groups and NHS regions, estimate a measure of ongoing transmission and predict the number of new COVID-19 deaths.
We use:
Data are stratified into eight age groups: <1, 1-4, 5-14, 15-24, 25-44, 45-64, 65-74, 75+, and the NHS England regions (North East and Yorkshire, North West, Midlands, East of England, London, South East, South West).
Value of \(R_t\), the average number of secondary infections due to a typical infection today.
The percentage of a given group that has been infected.
NB: negative growth rates are rates of decline. Values are daily changes.
| Region | Median | 95% CrI (lower) | 95% CrI (upper) |
|---|---|---|---|
| England | 0.00 | -0.01 | 0.01 |
| East of England | 0.02 | -0.02 | 0.04 |
| East Midlands | -0.01 | -0.03 | 0.01 |
| London | 0.01 | -0.01 | 0.03 |
| North East | -0.04 | -0.07 | -0.01 |
| North West | -0.05 | -0.08 | -0.02 |
| South East | 0.01 | -0.02 | 0.03 |
| South West | 0.01 | -0.01 | 0.04 |
| West Midlands | -0.01 | -0.03 | 0.01 |
| Yorkshire and The Humber | -0.05 | -0.08 | -0.03 |
Halving times in days, if a region shows growth than value will be NA.
| Region | Median | 95% CrI (lower) | 95% CrI (upper) |
|---|---|---|---|
| England | NA | 68.35 | NA |
| East of England | NA | 45.32 | NA |
| East Midlands | 111.75 | 22.81 | NA |
| London | NA | 48.12 | NA |
| North East | 18.49 | 9.77 | 65.20 |
| North West | 14.47 | 8.85 | 32.18 |
| South East | NA | 36.42 | NA |
| South West | NA | 45.94 | NA |
| West Midlands | 67.07 | 22.20 | NA |
| Yorkshire and The Humber | 12.72 | 8.18 | 23.73 |
Doubling times in days, if a region shows decline then the value will be NA.
| Region | Median | 95% CrI (lower) | 95% CrI (upper) |
|---|---|---|---|
| England | 589.56 | 57.27 | NA |
| East of England | 41.91 | 15.80 | NA |
| East Midlands | NA | 53.35 | NA |
| London | 60.00 | 21.16 | NA |
| North East | NA | NA | NA |
| North West | NA | NA | NA |
| South East | 109.11 | 23.12 | NA |
| South West | 58.96 | 18.52 | NA |
| West Midlands | NA | 94.38 | NA |
| Yorkshire and The Humber | NA | NA | NA |
NB: negative growth rates are rates of decline. Values are daily changes.
| Region | Median | 95% CrI (lower) | 95% CrI (upper) |
|---|---|---|---|
| England | 0.00 | -0.01 | 0.01 |
| East of England | 0.02 | -0.01 | 0.05 |
| East Midlands | 0.00 | -0.02 | 0.03 |
| London | 0.02 | -0.01 | 0.04 |
| North East | -0.02 | -0.04 | 0.00 |
| North West | -0.04 | -0.05 | -0.02 |
| South East | 0.01 | -0.01 | 0.04 |
| South West | 0.02 | 0.00 | 0.05 |
| West Midlands | 0.00 | -0.02 | 0.02 |
| Yorkshire and The Humber | -0.04 | -0.05 | -0.02 |
Halving times in days, if a region shows growth than value will be NA.
| Region | Median | 95% CrI (lower) | 95% CrI (upper) |
|---|---|---|---|
| England | 497.46 | 74.06 | NA |
| East of England | NA | 54.54 | NA |
| East Midlands | NA | 41.09 | NA |
| London | NA | 96.84 | NA |
| North East | 30.67 | 15.59 | NA |
| North West | 18.64 | 12.87 | 40.48 |
| South East | NA | 95.96 | NA |
| South West | NA | 189.44 | NA |
| West Midlands | NA | 40.87 | NA |
| Yorkshire and The Humber | 18.98 | 13.04 | 37.93 |
Doubling times in days, if a region shows decline then the value will be NA.
| Region | Median | 95% CrI (lower) | 95% CrI (upper) |
|---|---|---|---|
| England | NA | 109.47 | NA |
| East of England | 42.92 | 15.06 | NA |
| East Midlands | 151.55 | 27.24 | NA |
| London | 38.95 | 16.21 | NA |
| North East | NA | 2902.06 | NA |
| North West | NA | NA | NA |
| South East | 46.43 | 18.41 | NA |
| South West | 32.07 | 14.51 | NA |
| West Midlands | 294.04 | 31.27 | NA |
| Yorkshire and The Humber | NA | NA | NA |
The blue lines is show when interventions have been introduced (lockdown on 23 Mar and the relaxation of measures on 11 May), and the red line shows the date these results were produced (08 Dec).
The figure below shows the probability that \(R_t\) is greater than 1 (ie: the number of infections is growing) in each region over time. Clicking the regions in the legend allows lines to be added or removed from the figure.
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